Fix flaky checkout spec

This change adds a waiting matcher for the text on the page, instead of
asserting on the current_path which causes race conditions and
flakyness.

Author: forkata

templates/spec/system/checkout_spec.rb

@@ -599,8 +599,8 @@
       choose "Credit Card"
       fill_in_credit_card
       click_button "Save and Continue"
+      expect(page).to have_text('Put your terms and conditions here')
 
-      expect(current_path).to eq checkout_state_path('confirm')
       check 'Agree to Terms of Service'
       click_button "Place Order"
     end